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Area forecast discussion...updated 
National Weather Service Norman OK 
1102 am CDT Sat Sep 6 2008 


Update... 
complex of showers/thunderstorms shifting east of the forecast area this morning. Low 
clouds have developed over western portions of forecast area and will slowly 
erode/dissipate this afternoon in most areas. With cloud cover over 
portions of the forecast area... differential heating boundary could develop. 
With this boundary along with the front... additional showers/thunderstorms 
will be possible this afternoon into the evening. Moderate instability 
and some wind shear will develop this afternoon... so if storms 
develop... a few severe storms may be possible. Have pulled slight 
chance probability of precipitation further south to account for areas near and north of 
front... which includes those areas being strongly heated this 
morning. With low clouds and rain cooled air... temperatures still in the 
50s and 60s across parts of the area late this morning. Have 
lowered maximum temperatures to account for this... especially in northwest OK where 
clouds expected to hang on the longest. Also adjusted hourly grids 
and sky cover to show current trends. Will send updates shortly. 


Maxwell 
&& 


Previous discussion... /issued 643 am CDT Sat Sep 6 2008/ 


Update... 
updated forecast to reflect further progression to the east by the 
mesoscale convective system across northern Oklahoma... and to extend somewhat higher probability of precipitation 
into our east central zones. 


Previous discussion... /issued 338 am CDT Sat Sep 6 2008/ 


Discussion... 
as the models indicated last night... convection has developed early 
this morning across northern OK and southern Kansas in response to 
increasing warm advection around the 850mb level. Based on current 
radar trends we will go with high probability of precipitation this morning across 
northern Oklahoma with a fairly quick drop off towards central 
Oklahoma. The models indicate that the winds across the southern 
half of the County Warning Area will tend to veer more to the south today while an 
east to northeast flow will likely persist across northern 
Oklahoma... somewhat reinforced by the early morning activity. 
This should set up a surface boundary... likely near or north of 
I-40... marked both by backing winds and thermal gradient... as 
temperatures in northern Oklahoma will be cooler today. With the 
help of daytime heating... we should see scattered showers 
and thunderstorms develop near and north of the boundary this 
afternoon and evening. Meanwhile... a strengthening low level jet 
later tonight should once again result in showers and 
thunderstorms north of the surface front/boundary. We will again 
go with highest probability of precipitation near the Kansas border... dropping them off 
quickly towards central Oklahoma. 


The operational GFS and ensembles both indicate the County Warning Area will be 
generally situated along the southern edge of the westerly flow 
aloft during the early part of next week. While most of the 
forcing associated with the stronger upper flow will be to the 
north of the County Warning Area... it will be close enough to push another front 
into the area by late Monday... perhaps reaching the Red River 
valley Tuesday morning. A few showers and thunderstorms near the 
front will again be possible. 


By the middle of the week... the upper flow strengthens somewhat across 
the area while become more southwesterly. Weak short waves 
embedded in the southwest flow may generate a few showers and 
thunderstorms over the area through the second half of the week. 


MOS temperatures generally look reasonable and seem to be aware of the 
likelihood for cooler temperatures in the north today due to the 
rain/cloud cover... however we did undercut the MOS highs by a few 
more degrees. 


&& 


Preliminary point temps/pops... 
Oklahoma City OK 85 62 89 66 / 20 20 10 10 
Hobart OK 88 65 93 67 / 10 10 10 10 
Wichita Falls Texas 93 67 96 69 / 10 0 0 0 
gage OK 78 57 85 61 / 30 20 20 20 
Ponca City OK 73 61 84 66 / 80 50 20 20 
Durant OK 88 64 91 68 / 0 10 0 0 


&& 


Oun watches/warnings/advisories... 
OK...none. 
Texas...none. 
&& 


$$ 


25/24